Multiple motor driving mechanism for aircraft with adjustable propeller



March 19, 1946. F. NALLINGER ETAL A 2,396,745

I MULTIPLE MOTOR DRIVING MECHANISM FOR AIRCRAFT WITH ADJUSTABLE PROPELLER Filed Nov. 4, 1959 2 sheets sheet 1 'X-QML ATTORNEY MULTIPLE MOTOR DRIVING MECHANISM FOR AIRCRAFT WITH ADJUSTABLE PROPELLER Marh 19, 1946. I Y F. NALLINGER firm. 2,396,745

4 Filed Nov. 4, 1939 2 Sheets-Shet 2 INVENTORS FRITZ NAIJJNGER ALBERT rnnzomcu ATTORNEY.

Patented Mar. 19, 1946 MULTIPLE MOTOR; DRIVING mncnamsn FOB; AIRCBAET} WITH ADJUs'rn sr-n PIto PEL R Fritz sludg Stuttgart, a a a bert ried eh S tuttgart Ba'd,Cannstath G'" vested in; he mrtrC Wl Application masher 4, 19 39,Serial No. 302,820 nfietmanvb ber' 1;1938

Th si n i n relat oimultipl motordrivin mecha i m; especi a hough not necessarily: Qr a rcr t; ere n ne r'mpre adjustable pros pel ers. a d on r l n witha ism. V hereiorare. l9l e i nd he e n: the seve a mo orsc rive 1a el lmoh i hfi t inr uch a w y, that wheneve ione or nrore ofthe motors fail the prqpeller s or the like continue to be driven by the remaining ac: rewa er rrmpt i he primary object. of the uated] r r v Figure 2 ,is a similarview .on asmalle scale,

taken through another e bdci'riiento'fhthe in 3 in h; e ic z' g i ins i, q itrl mechanism ispneuniaticaHs aQtuate i ure 31 n' sech 'taken it rq hzpna gure rans erse Se on. akeni ns he e2,4;. o Fi ure 3- F gu e Fr i n axial eq l n t ken hrouehan: ther Q m'zQ 'p tqh c ntrol; m h nism.

Referring in detail to the. drawings, the several,

moto l nd. 2 d i e th prope l r ha t? t rough; claw clutches 3gandrespectively, and related gearings 5,1. 6 and 1.3 On the propellershaft "8 are -mounted .two" adjustable propeller blades. 9 and-1Ifl adjustably"rotatable nthe axes of the shafts "H; and I2 and adjustable by means 'of'the rods |.3'andl4, respectively; These rods" are con-' nected' to 'a' T-shap'ed piece I 5 slidable longitudinally 'ur thepropeller hub l 6; The :inner'end' l'5a' being fconnecte'd' to "the arms o'fthe crosshead' of the- T-piece, s'o' that when the shaft I 1 i'sturne'd it adjusts the T-piece and henceth'e propeller" blades-ina direction corresponding to the direction of rotation of the shaft I1.

The rearward end of the shaft l1 extends beyond the rear end of the propeller shaft 8 and has a pinion l8 meshed with a driving pinion l9 of a power or revolution controller 20 which is drawmgs the gearwheel2| isv arranged on a-shaftl driven by a gearwheel 2i meshed with a geari zi fixed onthe propeller shaft."

As shown in Figure 3; the gearwheel 211s fast; on a shaft 25,"an'd*thepihion' I this fast on'ash'aft 2B, the innermost endof-'ithe lattervbein'g sup ported in a'co'rresponding axial :bore of theisha'ft 25. The'shaftfii comprises'two radiallytproject-;. mg arms 21, and the' shaft 25 is provided with th-twosimilar'arms 28whichTare1angu1ar1y on. set byrelative to the arm's Z'L'and project'zinto the spaces between the'latter, springs: 29ia'reinserted between adjacent arms" 21 and'28lto hold said arms'resilientl'y' at predetermined distances from dne'another while 'pro'Vidinga' resilient coua' hnghetwe the sha'ftsli arm-I26 and thereby' between the gearwheelszland 19.

"Acontroll'er of this type operates as follows in the arrangement illustrated "in Figure llof the As apparent in Figure 1, thegearwheels 22 and I 8 have the same diameter and thelgearwheels 2t and '19 are of'the" samefdiameter'; so that the shaft" n1 rotates" Mummy and? synchronously? with "thepropeller shaft 8; 'Thesprm s 29 'tliei1 elfect a certain equilibrium between the shalts -8' and; [1, whereby a predeterminedpitch angle is obtainedjfor the propeller blades- 9- and 'luz ir;

tharesisltanceat the propeller blades li'ncreases; softha t the propeller tends to'redu'ce th speed of rotatior'iiof the propeller shaft and "driving metqr i he ro in a 'kjpre su l t the lqr 2 'a esj a e a ive: plac ment between the" shaft 251' 5 I nd s al-whee s 21; and l9; aha-fa; o respondin elat ve dju tme t f e. a ilialfyshafti'l'l to the, 'prqneller shaft 8. Tl 1i lat-f ter jrelativeiadju s'tment results in the smasher,

pitchris reducedi.

In the embodiment shown, in 'Figure 5 of, the.

30, the latter carrying ,a centrifugal gi lvern'or 311 having weights 32. The shaft 30 isfurther pro; videdwith helical guideribs 33 A sleeve 34 :18 arran ed a-t eshaft 30 and h s s e c nbe,

axially displaced on, the shaft. 30.; by means of the arms 35.- of. the wei hts. 32, andpwing to the; helical. ribs cooperating. with, corresponding, grooves inv the sleeve, 34;.said axial v displacementcauses a corresponding angular displacement between shaftiiltllriand' sleeve 34. The g'earwheel; I8 is mounted on theusleeve 34 axially displaceably but secured against rotation by means of the keys 3B. The gearwheel I9 is in mesh with the gearwheel I8, which may project through a suitable I5,. be ing, gpu l jd' rea'rwardlyf whereby the: L bl'adej aperture into the chamber of the controller housing 20 containing the gearwheel [9.

The device as a whole operates as follows:

With falling speed of rotation the weights 32 approach one another and shift the sleeve 34 toward the leftjsimiiltaneouslyrotating the" sleeve through a predetermined angle relative to the shaft 30. The gearwheel l9 takes a part in said 7 relative rotation and causes an angular displace- 10. peller shaft 8, thereby effecting;anadjustmentof ment of the auxiliary shaft I! relative to the prothe propeller blades relative to their hub.

It will be apparent that in the above described nd and third gear wheel is adapted to effect angular displacements between said second and third gear wheel in dependence upon variations of the torque transmitted by the propeller.

4. A driving mechanism, as claimed in claim 1, in" which said second and third gear wheel are arranged on a common fixed axis.

5. A driving mechanism, as claimed in claim 1, in which the size of said first gear wheel is equal to the size of said fourth gear wheel and the size ,of said second gear wheel is equal to that of said operations, the rotation of the propeller shaft 8 as driven by the motors I and 2, is transmittedbyj the gearwheels 22, 2|, l9 and I8 to the adjusting I shaft 11 and that the adjusting shaft 11 rotates under the influence of the controller 20, when the control action is constant, with the same speed as the shaft 8. In proportion to the increase or decrease of the number of revolutions. of the shaft 8, the controllerZD so acts as to change the angle between the auxiliary shaft l1 and the propeller shaft 8 by meansof the gearwheel l9,and hence the pitch of the propeller blades,

, It will be understood that the controllerZll may be constructed in anyvother suitable manner, and that hereinabove described maybe replaced by one electrically, hydraulically, or pneumatically actuated, and thesame applies to the common driving gearing 3, 4, 5, 6 and 1.

. In Figure 2 of the drawings is shown an embodiment of the invention in which apneumatic orhydraulic arrangement is provided for operating the pitch adjusting mechanism, in which arrangement the shaft of the T-piece I- is actuated by a hydraulic or pneumatic piston 23 to whose cylinder fluid under pressure is. conveyed under the control of a controller driven by means of a pump 24 drawn by the gearwheels I9, I8.;

What we claim is: '1. Ina driving mechanism for an, aeroplane propeller havinga hub, a propeller blade adjusta speed equal to that of [said second gear wheel" and to effect angular displacements between said second and third gear wheelindependenceupon variations of a selected, operating condition of. the propeller, an auxiliary'shaft carrying a fourth gear wheel in mesh with said third gear wheel to drive said auxiliary shaft at arotary'speedequal to that of the propeller shaft, and 'm'eans'to ad-- just the pitch position of the propeller blade relative to the hub in dependence'upon angular displacements between said propeller shaft and said auxiliary shaft.

2; A driving mechanism, as claimed in clai'm l, in which said coupling means between said sec- 0nd and third gear wheel is adaptedto effect a'ngular displacements between said second and third gear wheel in dependence upon variations in the speed of rotation of the propeller;

-3 A driving mechanism, as claimed in claim 1, inwhich said coupling means between said sec,-

third gear wheel whereby said auxiliary shaft rotates normally synchronously with the propeller shaft.

16. 'A'driving mechanism, as claimed in claim 1, in which said means for adjusting the pitch of the propeller blade includes cooperating elements rotatable with said propeller shaft and said auxiliary shaft, respectively.

'7. A driving mechanism, as claimed in claim 1, in which said means for adjusting the pitch of the propeller blade includes an axially displaceable'element arranged for rotation with said hub, means connecting said element with the blade for adjustment of the latter relative to the hub upon axial displacement of said element, and a screw coupling between the auxiliary shaft and said element.

8. A driving mechanism, as claimed in claim 1, in which the propeller shaft is hollow and said auxiliary shaft projects axially into said hollow propeller shaft.

9. A driving mechanism,- as claimed in claim 1, in which the propellershaft is hollow and said auxiliary shaft is rotatably and coaxially supported in said hollow-propeller shaft with its rear end projecting from the rear end ofthe latter,

said first gear wheel being secured-to the rear end of the hollow propeller shaft and'said fourth tween each of said motors and said gearing, each of said coupling means being: adapted to become inoperative if the torque transmitted fromitsassociated motor to said propeller shaft becomes negative, of an auxiliary shaft rotatably and coaxiallysupported in said hollow propeller shaft with its rear-end projecting'from the rear end of the latter, couplingmeans between the rear end of. the propeller shaft and the'rear end of the. auxiliary shaft to drive the auxiliary shaft normally at a speed equallto that of the propeller shaft andto effect angular displacements .between said propeller shaft and auxiliary shaft in dependence upon variations of a selected operat ing'condition of the propeller, and means to ad-.

just the pitch position of the propeller blade relative to the hub in dependence upon said angular displacements; between said propeller shaft and said auxiliary shaft. 7 a a.

o FRITZ NALLINGEB..-

ALBERT FRIEDRICH. 

